There are plenty of Big Data applications that aren't unethical. Back in the 90s (before the term Big Data was conceived) two of the biggest users of Teradata were P&G and Wal*mart. It was more about supply chain and retail store efficiency than anything nefarious. Big data helped make sure that store shelves had what people wanted.
Today there are mass spamvertising campaigns on Big Data, but there are also applications on financial services (making sure our pension funds take the right risk), engineering, telecom and elsewhere that help improve our lives.
Reducing retail waste is better for everyone. Though some of the stuff they do is questionable, like how carefully items in the store are placed to maximize the amount of unnecessary crap they sell to impulsive people.
Today there are mass spamvertising campaigns on Big Data, but there are also applications on financial services (making sure our pension funds take the right risk), engineering, telecom and elsewhere that help improve our lives.